1. Field of Invention
This invention pertains to an optical monitoring system. More particularly, this invention pertains to an optical monitoring system that compares an absorption spectrum of a filter with that obtained from a sample or specimen. The system uses a switching assembly enabling a plurality of filters to be used for the comparison.
2. Description of the Related Art
It is desirable to identify chemical and biological agents and other constituents in fast moving streams or in remote locations where the material to be examined is moving quickly. Examples where such identification is desired include fast moving streams of water, gas and materials, for instance, examining flows of milk for biological agents such as botulism and fast moving streams of water such as in municipal water supplies, where one can identify multiple chemical and biological agents of interest. In all these cases, successful interrogation requires the very quick identification of a number of predetermined constituents.
The sensing of spectral absorption, reflection, transmission and diffraction as a function of wavelengths, bandpass, and other spectral energy measurements allows for identifying both the geometry and composition of materials. Modern hyperspectral imaging (sensing at many wavelengths simultaneously) is able to collect extraordinary amounts of information at amazing speed. However, reducing the data from physical fields of signal values to high-level, useful information is difficult. Integrated computational imaging (ICI) is a process in which image information is encoded as it is sensed to produce information better suited for high-speed digital processing. Both spatial and spectral features of samples can be encoded in ICI. When hyperspectral images are simultaneously obtained and encoded at many different wavelengths, the process is called hyperspectral integrated computational imaging (HICI).
In many cases, it is desirable to inspect and quantify only preselected constituents in areas not easily accessible by ordinary sampling means. Physically extracting a sample can be difficult when exposing the sample to ordinary inspection means such as visual and laboratory analysis because these analyses can destroy the sample. In other cases, such inspection must be done in situ along with other processes.